Courtesy: Class X 2007

Locations

RohriKhairpurHyderabadThattaKarachiNooriabad

Dera Ghazi KhanDundotGharibwalJauharabadDaud KhelAttockRawalpindi

NowsheraCheratKohat

Location & FactorsLocation:There are 29 cement industries producing 1.8 million

tonnes of cement. The plants are located in Hazara, Cherat, Jhelum, Thatta, Kohat and Dera Ghazi Khan districts, and at Daudkhel, Rohri, Hyderabad, and Karachi.

Factors affecting cement industry’s locationThere are many favorable factors for the development of cement

industries locally:• Availability of raw materials(limestone and gypsum)• Good domestic market with high demand from the construction

industry• Natural gas and coal are used as a cheap fuel –easily available• Labor available at lower wages• Favorable government policies

Importance• Rank of Pakistan in Cement Export:• Pakistan has already joined the world club of

cement exporters, with 48th ranking among a totalof 116 exporting countries, having attained recently an export figure of USD 33.24 million.Some of the big players from Pakistan who can possibly play a major role in the export of cement to India are Lucky Cement, the largest cement producer in the country, DG Khan CementCo, Maple Leaf Cement, Attock Cement, among others.

High Quality of Cement:Pakistan produces good quality of cement. This is the main reason due to which recently Russia is offering high price for Pakistani cement. Globally Pakistan is recognized for producing good quality of cement due to which countries like Afghanistan, India, Middle east and some African countries prefer to import cement from Pakistan.

The main raw materials used in the cement manufacturing process are limestone, sand ,shale, clay and iron ore. The main material, limestone, is usually mined on site while the other minor materials may be mined either on site or in nearby quarries. Another source of raw materials is industrial by-products. The use of by-product materials to replace natural raw materials is a key element in achieving sustainable Development.

Cement Manufacturing ProcessThe raw materials needed to produce cement (calcium carbonate, silica, alumina, and iron ore) are generally extracted from limestone rock, chalk, shale, or clay. These raw materials are won from the quarry by either extraction or blasting. These naturally occurring minerals are then crushed through a milling process. At this stage, additional minerals are added to ensure the correct chemical composition for making cement. These minerals can be obtained from the waste or by-products of other industries, such as paper ash. Milling produces a fine powder, known as raw meal, which is preheated and then sent to the kiln for further processing. The kiln is at the heart of the manufacturing process. Once inside the kiln, the raw meal is heated to around 1,500 degrees C - a similar temperature to that of molten lava. At this temperature, chemical reactions take place to form cement clinker, which contains hydraulic calcium silicates.

In order to heat the materials to this very high temperature, a 2,000-degree C flame is required, which can be produced through the use of fossil and waste-derived fuels. The kiln itself is angled by 3 degrees to the horizontal to allow the material to pass through it, over a period of 20 to 30 minutes. Upon exiting the kiln, the clinker is cooled and stored, ready for grinding, to produce cement. A small amount of gypsum (3 percent to 5 percent) is added to the clinker to regulate how the cement will set. The mixture is then very finely ground to obtain "pure cement." During this phase, different mineral materials, called "additions," may be added alongside the gypsum. Used in varying proportions, these additions, which are of natural or industrial origin, give the cement specific properties, such as reduced permeability, greater resistance to sulfates and aggressive environments, improved workability, or higher-quality finishes. Finally, the cement is stored in silos before being shipped in bulk or in bags to the sites where it will be used.

Raw Materials

IRONORE SHALE LIMESTONE

CLAY

http://www.lafarge-na.com/wps/portal/na/en/2_2_1-Manufacturing_process

• Production of cement is a continuous process. Raw materials are dried, ground, proportioned and homogenized before being burnt in rotary kilns. The resulting Product 'clinker' is pulverised with gypsum at the grinding stage to obtain cement.

The finished cement is then pumped into cement silos from where it goes to packing plant for bag and bulk loading. Bulk cement is loaded into special tank trucks for delivery to customers' portable silos at construction sites or is trucked to Indocement's port facilities. Through road tankers and rail wagons.

Products and usescement is a binder, a substance used in construction that sets and hardens and can bind other materials together. The most important types of cement are used as a component in the production of mortar in masonry, and of concrete, which is a combination of cement and an aggregate to form a strong building material.

Problems faced by the industry1.Increased freight charges( Railways)2.Logistic problems(Poor transportation system)

3.Usage of Paper bag instead of plastic bags for export4.Idle capacity of various players5. Indian and Iran industry is also expanding its cement capacity6. High energy prices7. Decrease profitability due to competition in cement industry locally8. High level of taxation

 

• Emission Of Harmful Gases In Air

• Noise Pollution

• Soil Pollution

Problems faced by the Environment

Solutions:

1.Use of alternative fuels and by-products materials2.Green cement Green cement is a cementitious material that meets or exceeds the functional performance capabilities of ordinary Portland cement by incorporating and optimizing recycled materials, thereby reducing consumption of natural raw materials, water, and energy, resulting in a more sustainable construction material.New manufacturing processes for producing green cement are being researched with the goal to reduce, or even eliminate, the production and release of damaging pollutants and greenhouse gasses, particularly CO2.Growing environmental concerns and increasing cost of fuels of fossil origin have resulted in many countries in sharp reduction of the resources needed to produce cement and effluents (dust and exhaust gases)

NOV 2003/Paper 2/Q:3 ::

Clay or shaleprocess B

rotary kilnprocess A

process C

Calcium Sulphate(gypsum)

cement

powdered coalX

Q3: (a)[i] Name the Inputs shown? [2][ii] Name the important input X and state a major source of that raw material. [2][iii] Give the letter and the name of 2 of the processes A , B , C. [2]

[iv] Why is cement so important for the development of Pakistan? [5]

NOV 2005/Paper 2/Q:4(c)[i][ii]Q: [i] Name main locations in Pakistan for the Cement Industry? [4][ii] State TWO inputs and TWO Outputs of The Cement Industry? [4]

Factors influencing development of cement industry

Special Machinery

Raw Material

Energy Supply

Labour Supply

Questions Look at the fig. below, which shows a number of factors contributing to the development of the cement industry in Pakistan.

Using the information in fig. and from your own studies, explain why the cement industry has developed at a number of locations in Pakistan during recent years. [6]

June 91/ P2 / Q4(c)

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